Factory Heated Seats Failure

Not mine, just saw on Facebook. But yeah it might have fried a chip on the board too. It should be ok to test bypassing the pin with wire first to test the board and add the thermal limiter after if so. I don't know what those cost...I expect fairly cheap.

 

it was $6 for a 10 pack so it was worth a shot before ordering a new harness assembly... but i just did that

 

Took my truck last week to the dealer for diagnosis of what we all already knew was the problem. A week later the parts are in and I scheduled an appointment for this week to get my butt warmer fixed.

 

anybody getting an electrical fire smell as the seats are malfunctioning, like burning wires or do they just stop working and you see the burnt plug when checking things out?

 

I just want to share my own issue.
Had exactly that problem with the power pin melt and i just soldered a wire to the module and make the junction and it's working just like before.

I'm pretty sure the pin that is inside the connector was loose so it arcked up to the melting point.

 

I had the dealer repair my drivers side seat. Total was about $1,000. I paid less than that for the Platinum warranty so I am ahead

 

Big thanks to Mike here to help me get the parts I needed. I'm not much of a electrical guy but can handle a few wire splices. Should receive my new seat heater next week and I'll get it all together & report back. I'll be hanging on to the extra parts/old parts just incase. Thanks again!

 

My pleasure!! I am glad to be of service.

Also (shameless plug) if anyone needs anything in BC, I'm a parts advisor in Surrey. Glad to help where I can. I'll give forum members (And BCToyota4wd/4wdabc members) discounts where I can!

 

Hey Mike I live in BC and having a hell of a time finding parts that will work for me. I have no problems slicing wires if I have to, as my plan was to find a wreck. My heater amp is fried like the photos show from this thread.

 

Hi Jess. My son needs a heater unit as well and all the wrecking yards will not sell parts from seat....I'd have to buy the complete seat.

He said to find a wrecker that has a "write-off" truck. That's generally a truck with air bags all deployed in a bad accident.

I've run into a dead end trying to find one here.


Good Luck

 

I would look for a seat that blew the side airbag, they should part one in that condition.

 

Just as a follow up - Spliced the wires on the weekend, hooked everything back up and my seat heaters are working again like new. Good timing as we have a bit of a cold snap going through right now!! Thanks again to Mike and this forum.

 

Same issue on a 2016 trd off-road! 50k miles. Does anyone know a good fuse size I could throw in with an inline fuse to possibly stop it from happening again? Also was able to get a new amp from the dealership. Runs ~100$. Will not be needing it however because I was able to get the amp working again by simply cleaning out the connector of melted plastic. Tested the connectivity of the board, then plugged into passenger seat to confirm it was working. Just need a new male connector and some wire soldered in and she should be working like new!

update: just took a simple repin of the male connector.

 

Im case anyone is wondering, here's a pic of the new harness assembly with the new amp on it. It has a new part number but looks identical. They added a black retaining clip into the connector to try to keep it more stable

 

mine had this, still went out.

 

Yes someone stated earlier that the problem is the wattage moving through different gauge wires through out the assembly... If that was a true root cause I could see it not making a difference. Or it's probably a combination, and the undersized wires get too hot, and the loose connector sparks out and melts up

 

In the op pic there are two obviously fried components, probably fets(like solid state relays) which control the current. As with the blower module they generate more heat on the low-medium settings but for a different reason. It's likely that there isn't enough heat sinking for those components so the part from them to the connector pin burns out b

 

Same issue just happened on the drivers seat of my 2016 Toyota Tacoma TRD sport. I just got off the phone with Toyota Canada and they say there is nothing they can do for me where the warranty is out on it. I stressed to him this should be a safety recall. This is rediculous.

 

I've experienced the same issue with the driver side seat on my 2016 Taco TRD Offroad... just got off the phone with Toyota Canada and they're not willing to help as my truck has 93000Kms. The service guy at my local dealer confirmed that there's a TSB for both Canada and the US for this issue but that they're only covering vehicles that are less than 3yrs/60000kms. The gal that I spoke with at Toyota Canada said that if it's a common problem that they will only cover it beyond the 3yr/60k if they get enough complaints for the same issue and she encouraged me to tell anyone I know with the same issue to call/complain. She did also say that if I were to pay for the repair out of pocket that if they end up with what she called a "service extension" for the issue that I could apply to get reimbursed. I said that with my luck I'd pay and it would never be reimbursed so I wasn't willing to take that chance. The dealer quoted aprox$380 plus a couple hours labour... which would put the repair in the $700-$800 range. So My advice... call and complain if you're having the same issue... It's the only way we'll ever get them to pay for the repair.

 

Interesting fact for people that had been dealing with blown seat heater control modules, the latest parts catalog update added that part back into the catalog as something that can be ordered separately. Part number listed is 87501-0C020, which is what people were trying to order before without luck. It appears this part number is now in the system as orderable and so should be easier to get moving forward. May take some time before online parts stores update their websites to not show it as discontinued.

Getting the connector from Toyota will only be available with the seat heater element (which includes the module), but at least there may be a source for modules once stock is acquired for the distribution network.

If you really do need the connector as well, it can be sourced separately from Molex:

39-01-4050 - Housing, Connector
39-00-0078 - Terminal, Connector (For 16 AWG Wire; Qty: 5)
39-00-0039 - Terminal, Connector (For 18-24 AWG Wire; Qty: 5)

I have not verified the size of wire that is used, so have provided both size terminals here. I would expect it to be in the 18-24 range, but it may be larger.

It seems that Toyota or the seat heater manufacturer started using a CPA (connector position assurance) on the Molex connector (the little black plastic piece designed to prevent the connector from accidentally being disconnected), however I can't seem to find any evidence that the CPA is from Molex, so it will need to be reused if replacing the connector itself. Molex offers an improved version of the connector with both TPA and CPA, however I suspect it may not quite clear the housing on the module to latch in place without trimming. Molex rates these connectors for 13A per terminal. I am not sure if the harness side or the module side is entirely to blame. I've never been a fan of these types of connectors though, wish they used something different. If it was me, I'd probably depin the Molex connector from the PCB if I kept having issues with the latest pieces. Kind of surprised Toyota hasn't changed things with these, it's been an issue on several North American-produced models over the last decade.

Jeff